Saturday, January 16, 2010

Ferruginous Ducks and -hybrids

Earlier this week, I went to Vilamoura, in the Central Algarve, to the main observatory near the ETAR (sewerage-work) in the "Parque Ambiental". After parking the car, I flushed a Squacco Heron out of the ditch right next to the path. Penduline Tits were present and I could see one bird well. Marsh Harrier, Common Waxbill and calling Cetti's Warblers were other typical and expectable birds along the way my. After reaching the hide at the small lake, surounded by reeds, at first, only Common Coots, Great Cormorants, Little Grebes and some Mallard seem to be present - only a few birds in total, wich is nothing unusal there. The Marsh Harrier showed up from time to time, a Kingfisher crossed the lake and then, a first Ferruginous Duck (Aythya nyroca) swam out of the cover and was just visible beyond the small reedbed in front of me. A first winter male, in my opinion, still without the white eye of the adult. At least the bird looked "normal" for the species to me. I observed the bird for about 15 Min., during his diving-action at the edge of the reeds, where it probably fed on the common (introduced) freshwater Crayfish-species Prokambarus clarkii wich is also one of the favourits of the local Otters (lutra lutra) wich show up occasionaly in the Marinas of Vilamoura nad Faro, by the way.
Then a second bird- and a few Min. later, a third bird showed up. These two birds, were both a product of Hybridisation with Common Pochard (Aythya ferina).
At my previous visit, in early December 2009, there were 2 "normal" adult males present, plus one bird, wich could have been the second of the Hybrids shown further down. So, 2 of, at least 5 different "Ferruginous Ducks" observed at the location this winter, were Hybrids. I have seen and photographed this type of Hybrids at Lagoa dos Salgados, about 15kms further west, in earlier years already, wich is the only site, were the species is known to have bred with succsess in recent years.

Ferruginous Duck (Aythya nyroca). A "normal" first winter -male. Note the colour-tone, hardly contrasting between flanks and breast. Head- and bill-proportions and the bright white and clear defined undertail-patch. Vilamoura, 14-01-2010.

Hybrid of Ferruginous Duck and Common Pochard (Aythya nyroca x ferina) an adult male. Note the greyish flanks, yellowish eye, colour-tone on head and breast and the head and bill-shape. The confusion species Aythya americana has a different, more roundish head-profile and different markings on the bill. the following two photos are showing the same Individual. Vilamoura, 14-01-2010.

The following two photos show the third Individual present that day, also a Hybrid obviously, of the same species, apparently. A first winter or a female Individual ?

Hybrid of Ferruginous Duck and Common Pochard (Aythya nyroca x ferina). Vilamoura, 14-01-2010.

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